It has been known that antibacterial metals, for example, Ag, Cu, Zn and the like, have an antibacterial activity. Therefore, in the case where a product having a glass layer, such as a ceramic product, an enameled product and the like, having an antibacterial activity is to be produced, a process for stain resistant treatment is carried out, which has an antibacterial treatment step of imparting antibacterial function to a surface of a base body, such as a glass molded article, a ceramic molded article, a metallic molded article and the like. The antibacterial treatment step of the process for stain resistant treatment contains a preparation step of preparing a glazing material capable of forming a glass layer containing an antibacterial metal, and a vitrification step of forming a glazing material layer formed with the glazing material on the surface of the base body and melting the glazing material layer to form a glass layer.
According to the process for stain resistant treatment, a product is obtained that comprises a base body having a glass layer, and the glass layer comprises the glazing material. In the product having a glass layer thus obtained, the antibacterial metal in the glass layer can affect bacteria to kill them or to suppress propagation thereof.
An ordinary ceramic product comprises a ceramic main body and a glass layer formed on the surface of the ceramic main body.
The ceramic product is produced roughly in the following manner. As a preparation step, a base material that can form a ceramic main body and a glazing material that can form a glass layer on the surface of the ceramic main body are prepared. As a glazing step, a glazing material layer comprising the glazing material is formed on the surface of the base material. Thereafter, as a baking step, the base material and the glazing material layer are baked to obtain a ceramic product comprising the ceramic main body and the glass layer.
In the ceramic product thus obtained, the glass layer finishes the surface being smooth and fine, and makes the surface being difficult to be damaged and having water-proofing property.
Furthermore, ceramic materials used as products, such as table wares, kitchen equipments, ornamental articles, tiles, sanitary goods, electric equipments, physical and chemical equipments, industrial equipments, roof tiles, ceramic pipes and the like, comprise a ceramic main body as a base body and a glass layer formed on the surface of the ceramic main body. Enameled product comprises a metallic main body as a base body and a glass layer formed on the surface of the metallic main body. Further, part of glass products comprises a glass main body as a base body and a glass layer formed on the glass main body.
Among the foregoing products having a glass layer, a ceramic material, for example, is produced roughly in the following manner. As a preparation step, a base material that can form a ceramic main body and a glazing material that can form a glass layer on the surface of the ceramic main body are prepared. As a glazing step, a glazing material layer comprising the glazing material is formed on the surface of the base material. Thereafter, as a baking step, the base material and the glazing material layer are baked to obtain a ceramic product comprising the ceramic main body and the glass layer. In the product, the glass layer is finished to have a surface being smooth and fine, the surface is difficult to suffer formation of flaws, and water-proofing property is imparted.